Slow responding by older adults can impair perceptual-motor functioning as well as interfere with more complex processes of perception, learning, and memory. Deficits in these areas can be of considerable significance for the personal and social adjustment of the older person. The proposed research examines behavioral slowing from the standpoint of operant conditioning methods and concepts. Operant methods, by emphasizing the steady-state behavior of experienced subjects, provide data less influenced by the stress of performance evaluations in unfamiliar environments. Single subject designs give recognition to the increased between-subject variation that accompanies advancing age. The conceptual focus on control and modification of behavior by environmental contingencies provides a basis for testing the limits of behavior change in the face of biologically determined deficits. The experiments compare performances of healthy older (62+) and younger adults under conditions in which responses must be learned and executed under time constraints. Both complex operant schedules and more traditional tasks (e.g., card sorting, coding) are used to address two broad questions: can age-related deficits be remediated by schedules which reinforce rapid responding, and will improvements transfer to other schedules and tasks. Specific procedures include schedules which adjust response requirements according to current performances, which reinforce behaviors associated with more liberal decision criteria, and which shape appropriate divisions of attention to complex discriminative stimuli. The research is guided by several interrelated hypotheses: that deficits ordinarily seen with increasing age will be reduced or absent in active, healthy individuals thoroughly familiarized with the laboratory procedures; that deficits are a function of inadequate current experience with contingencies requiring rapid responding; and that deficits can be remediated through training procedures involving close stimulus control and reinforcement of elements of complex response sequences. Longterm objectives are to identify areas of deficit in the older adult and to develop ways of restoring competent performances through manipulation of contingencies of reinforcement.